static string GetDefaultConfigFile(string assemblyFile) {
	string configFilename = assemblyFile + ".config";
	if (File.Exists(configFilename))
		return configFilename;
	return null;
}

public ExecutorWrapper(string assemblyFilename, ...) {
//...
	assemblyFilename = Path.GetFullPath(assemblyFilename);
//...

}
public AssertActualExpectedException
(object expected, object actual, ...) {
//...
	this.actual += String.Format("(0)", actual.GetType().FullName);
	this.expected += String.Format("(0)", expected.GetType().FullName);
	//...
}